An unknown sample of Cu2+gave an absorbance of 0.262. Then 1.00 mL of solution containing 100 ppm (ug/mL)Cu2+was mixed with 95.0 mL of the unknown and the mixture was diluted to 100 mL in a volumetric flask with deionized water. The absorbanceof the new solution was 0.500. a.Denoting the initial unknown concentrationas [Cu2+]i,write an expression for the final concentrationafter dilution [Cu2+] b.Find [Cu2+]in the unknown.

An unknown sample of Cu2+gave an absorbance of 0.262. Then 1.00 mL of solution containing 100 ppm (ug/mL)Cu2+was mixed with 95.0 mL of the unknown and the mixture was diluted to 100 mL in a volumetric flask with deionized water. The absorbanceof the new solution was 0.500. a.Denoting the initial unknown concentrationas [Cu2+]i,write an expression for the final concentrationafter dilution [Cu2+] b.Find [Cu2+]in the unknown.

Fundamentals Of Analytical Chemistry

9th Edition

ISBN:9781285640686

Author:Skoog

Publisher:Skoog

Chapter16: Applications Of Neutralization Titrations

Section: Chapter Questions

Problem 16.20QAP

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The Handbook of Chemistry and Physics (http://openstaxcollege.org/l/16Handbook) gives solubilities of the following compounds in grams per 100 mL of water. Because these compounds are only slightly soluble, assume that the volume does not change on dissolution and calculate the solubility product for each. (a) BaSeO4, 0.0118 g/100 mL. (b) Ba(BrO3)2H2O, 0.30 g/100 mL. (c) NH4MgAsO46H2O, 0.033 g/100 mL. (d) La2(MoO4)3, 0.00179 g/100 mL
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An unknown sample containing mixed alkali (NAOH, NaHCO3, or NazCO3) was analyzed using the double flask method. A 250 mg sample was dissolved in 250 mL CO, free water. A 20.0 mL aliquot of this sample required 11.3 mL of 0.009125 M HCI solution to reach the phenolphthalein end point. Another 29.0 mL aliquot of the sample was titrated to the bromocresol green endpoint using 31.1 mL of the standard acid. What is/are the component/s of the sample? O NazCO3 only NaHCO3 only O NAHCO3 and Na>CO3 NaOH and NazCO3 O Cannot be determined
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A dried sample of commercial salt was prepared by a coning and quartering. A 0.911-g sample of the salt was dissolved and diluted to 250.0 mL in a volumetric flask. Repeat 10.00-mL aliquots of this solution were titrated with a 0.054 M silver nitrate solution, requiring 9.68 mL to reach equivalence. Calculate the %(w/w) NaCl in the original sample.